Tempered glass used as an exterior material for electric/electronic products has low impact strength, has difficulty reducing product weight due to high specific gravity, and has a problem of high manufacturing costs and high probability of breakage due to poor processability and tractability. In order to address these problems, transparent resins are used instead of tempered glass.
Examples of transparent resins used in products requiring transparency include polycarbonate resins, transparent acrylonitrile-butadiene-styrene (ABS) resins, styrene-acrylonitrile (SAN) resins, polystyrene resins, and poly(methyl methacrylate) (PMMA) resins. Polycarbonate resins have good transparency and impact resistance, but have a problem of high price and insufficient scratch resistance and chemical resistance. Transparent ABS resins such as a methylmethacrylate-acrylonitrile-butadiene-styrene (MABS) resin can secure transparency and impact resistance, but have poor properties in terms of scratch resistance, heat resistance, and the like. Moreover, SAN resins, polystyrene resins, and PMMA resins are difficult to use as exterior materials due to insufficient impact resistance thereof, despite advantages of low price and high transparency.
Therefore, there is a need for a transparent thermoplastic resin composition which has excellent properties in terms of scratch resistance, heat resistance, impact resistance, transparency, and balance therebetween and thus can be used as an exterior material for electric/electronic products (for example, as a substitute for tempered glass).